JSFiddle - React, Tailwind, and code Playground

HTML

<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>
<div class="blueDiv toBeFaddedIn"></div>

CSS

.blueDiv {
    background-color: blue;
    height:50px;
    width: 50px;
    display: none;
    
}

JavaScript

function sequentialFadeIn(selectorText, speed, display, callBack) {

    display = typeof display !== 'undefined' ? display : "block";

    function helper() {
        nextElementToFadeIn = $(selectorText).not(".alreadyFadedIn").first();
        nextElementToFadeIn.fadeIn(speed, function() {
            $(this).addClass("alreadyFadedIn");
            helper();
        }).css("display", display);
    }
    helper();



    callBack(selectorText);
}
sequentialFadeIn(".toBeFaddedIn", "fast", "inline-block", function cleanUp(selectorText1) {
    $(selectorText1).removeClass("alreadyFadedIn");
    console.log("Clean up has been performed.");
    console.log("Selector text:" + selectorText1);
});